Code Division Multiple Access (CDMA) 1X refers to the first phase of CDMA 2000. A forward link data rate may reach 144 Kbps. Packet switching is introduced to a network part, which can support a mobile Internet Protocol (IP) service. A CDMA 1X network may serve as a platform for bearing a voice service, and may also serve as a platform for bearing packet data of wireless access to the Internet. It not only can provide a conventional voice service for a user, but also can provide a data service in end-to-end packet transmission mode for the user.
The CDMA2000 1X EV-DO standard originates from a High Data Rate (HDR) technology of the Qualcomm company. Qualcomm proposed the concept of HDR to the CDMA Development Group (CDG) as early as in 1997. An official technical solution entitled CDMA2000 1X EV-DO was submitted to the 3rd Generation Partnership Project 2 (3GPP2) in March 2000 after constant improvements and experiments. 1X EV means ‘Evolution’ and indicates a development of the standard. DO means Data Only or Data Optimized, indicating that the EV-DO technology is an efficient method for enhancing a CDMA2000 1X network in the aspect of providing a data service.
At present, a CDMA2000 1X EV-DO system (DO system for short) provides a data service for a terminal, and separates a high-rate packet data service from low-rate voice and data services. The high-rate packet data service is provided by an individual carrier, whereas a conventional low-rate voice service and a medium- and low-rate packet data service are still provided by a 1X system. The Qualcomm company provides an interoperability rule of a hybrid access terminal (HAT) to achieve compatibility and interoperability of the DO system and the CDMA2000 1X system (1X system for short). The HAT includes a 1X/DO dual-mode terminal. The rule specifies that a voice service preferentially access the 1X system, whereas the data service preferentially access the DO system. Therefore, when the HAT performs the data service in a 1X/DO hybrid system, the DO system is accessed preferentially.
To increase spectrum efficiency, in the 1X/DO hybrid system, in a case that the DO system that preferentially processes the data service has a high load whereas the 1X system has a low load, an operator expects that the 1X system is capable of sharing the load of the DO system to balance the loads of the DO system and the 1X system. However, no technical solution in the prior art is capable of solving a problem of balancing loads between the DO system and the 1X system.